Photostability study of europium dibenzolymethide embedded in polystyrene thin films with high concentration

The europium dibenzolymethide has been embedded with high concentration in a polystyrene matrix using spin-coating deposition. We have investigated th e temporal stability of the film in measuring simultaneously the intensity I and decay time tau of fluorescence and the sample transmittance T at the excitation wavelength. The low bleaching efficiency is measured in the orde r of 10(-4). During the photobleaching process, it appears that there are s ome non-monotonous fluctuations on tau and T, whereas I decreases continuou sly, depending on the film thickness d and the chromophore concentration N- 0. In addition, we show that these films can be used to probe a metallic su rface by means of the quenching effect. (C) 2000 Elsevier Science B.V. All rights reserved.